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VI. INDIVIDUAL WORK

Task 1. Read the text about the historical development of

satellite geodesy. Put the paragraphs in the correct order and
translate into Ukrainian.

Historical Development of Satellite Geodesy
The development of satellite geodesy can be divided into several

phases of about one decade each.
_____ Surveyors began to use satellite techniques in geodesy,
geodynamics, and surveying in 1980 years. Two aspects in particular
are remarkable. Satellite methods were increasingly used by the

surveying community, replacing conventional methods. This process
started with the first results obtained with the NAVSTAR Global
Positioning System (GPS) and resulted in completely new

perspectives in surveying and mapping. The second aspect concerned
the increased observation accuracy. One outcome was the nearly
complete replacement of the classical astrometric techniques for
monitoring polar motion and Earth rotation by satellite methods.

Projects for the measurement of crustal deformation gave remarkable
results worldwide.

_____ Phase of the scientific projects includes new observation
techniques, which were developed and refined in the years 1970-1980,
in particular laser ranging to satellites and to the Moon, as well as
satellite altimetry. The TRANSIT system was used for geodetic

Doppler positioning. Refined global geoid and coordinate
determinations were carried out, and led to improved Earth models
(e.g. GEM 10, GRIM). The increased accuracy of the observations

made possible the measurement of geodynamical phenomena (Earth
rotation, polar motion, crustal deformation). Doppler surveying was
used worldwide for the installation and maintenance of geodetic
control networks (e.g. EDOC, DÖDOC, ADOS).

_____ Phase of the international and national permanent services
in connected with the years 1990 to around 2000. In particular two
large international services have evolved. The International Earth

Rotation Service IERS, initiated in 1987 and exclusively based on
space techniques, provides highly accurate Earth orientation
parameters with high temporal resolution, and maintains and
constantly refines two basic reference frames. These are the

International Celestial Reference Frame ICRF, based on

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